What does 說樂君子 (열락군자) mean?

In the first passage of his Analects, Confucius asks three seemingly unrelated, rhetorical questions. Why? Maybe because they are related? Here are the three questions:

學(학)而(이)時(시)習(습)之(지), 不(불)亦(역)說(열)乎(호)?

 “To study (學) and (而) frequently (時) practice (習) it (之), is [that] not (不) indeed (亦) enjoyable (說乎)?” 

有(유)朋(붕)自(자)遠(원)方(방)來(래), 不(불)亦(역)樂(락)乎(호)?

“To have (有) friends (朋) from (自) far (遠) regions (方) come (來), is [that] not (不) indeed (亦) joyous (樂乎)?” 

人(인)不(불)知(지)而(이)不(불)慍(온), 不(불)亦(역)君(군)子(자)乎(호)?

[If] a person (人) is ignorant (不知), but (而) not (不) resentful (溫), is [he] not (不) indeed (亦) a gentleman (君子乎)?

Why start a text with such questions? Confucius seemed to be answering a question that, for some reason, is missing from the text. What was the question? I think one can get clues to the question from the answer given by Confucius.

What do all three rhetorical questions have in common? They all ask, "Is that not (不) indeed (역)...?" The first question asks, "Is that not indeed 說 (열)"; the second, "Is that not indeed 樂 (락)"; and the third, "Is he not indeed 君子 (군자)," creating the 4-character phrase 說樂君子 (열락군자). The character 說 (설) means "to speak," but it can also mean "to be happy" or "to enjoy," in which case it would be pronounced "열" in Korean and have the same meaning as 悅 (열). The characters 悅樂 (열락) could have two meanings. One is "to love (悅) music (樂)," and the other is "to take pleasure in." That means 悅樂君子 can be translated as either "A gentleman who loves music" or "Take pleasure in being a gentleman," or maybe Confucius intended it to include both meanings.

I have read that Confucius loved to play music and even taught his disciples to play music, so he apparently believed a gentleman should play music. Therefore, the question may have been, "Why does a gentleman play music?," to which Confucius answered, "To study and frequently practice it, is that not enjoyable?" Also, if a gentleman can play music, maybe his friends will travel from distant regions to hear it?

Or maybe the question was, "Why should a person take pleasure in being a gentleman?" to which Confucius gave the above answers.

That is all I really have to say right now. Last night I picked up my copy of "The Analects of Confucius" and read the first passage, a passage that has always bothered me because the rhetorical questions seemed to come from out of the blue. That was when I started looking for possible hidden meanings and noticed the characters "說樂君子 (열락군자)."